This invention relates to applicators and more particularly to an applicator for simultaneously applying an adhesive and sealant in a first bead and a foamable material in a separate second bead to the periphery of glass to be installed in a motor vehicle.
In the manufacture of motor vehicles, such as automobiles and trucks, the front windshield and the rear window are commonly mounted by means of a sealant and adhesive material which maintains the glass article in position and provides a barrier against water. A polyurethane material is commonly employed for this purpose and is applied on the glass in a shaped bead after which the glass is inserted into a mating flange formed on the vehicle. As an additional sealant and for noise reduction, a second bead of a rubberlike foam material is applied interiorly of and adjacent to the first bead.
The polyurethane bead is applied and cured at substantially room temperature. On the other hand, the foam bead usually consists of a foamable hot melt wherein foaming is the result of a chemical reaction triggered by heat. For this reason, the foam bead is generally, applied at a temperature of about 300.degree. F. Because the polyurethane bead must retain its shape for satisfactory application and since the material tends to flow at elevated temperatures, it was the common practice to apply the beads of polyurethane and the foamable material separately. Such separate applications necessitated the use of separate robot devices for applying the two materials and separate workstations for each. This had the obvious disadvantage of substantial capital costs and an increase in the manufacturing time.